Air-oil separator and method of separation

Abstract

An air-oil separator operating on an updraft principle for use with gasoline and diesel internal combustion engines. The separator includes a housing having an inlet and an outlet located at the upper end of the housing. Air-oil mixtures are introduced into the upper portion of the housing, flow downward with a vortex action, are deflected by a baffle at the bottom of the housing and reverse their flow to enter a conduit extending from the outlet and opening into the interior of the housing at a point near the baffle. The inlet has a smaller cross-sectional area than the outlet producing a reduction in pressure of the air-oil mixture. The reduction of pressure, vortex action, deflection and flow path reversal cause oil and contaminants in the stream to be deposited at the bottom of the housing where they are removed by means of a drain.

What is claimed is: 
     
       1. An apparatus for separating oil and contaminants from air-oil contaminant mixtures from the crankcase of an internal combustion engine comprising: a housing;   an intake inlet conduit of a first cross-sectional area communicating with the interior of the housing at a first end thereof;   an exhaust outlet conduit of a second cross-sectional area greater than said first cross-sectional area communicating with the interior of the housing, said outlet conduit being located at said first end of the housing whereby the gas pressure of said mixtures admitted into the unit is reduced in the flow from said inlet conduit to said outlet conduit;   said outlet conduit extending from the exterior into the interior of the housing a substantial distance from said first end toward an end of the housing opposite said first end;   a baffle located between said opposite end of the housing and the inlet conduit in the interior of the housing in the flow path of said mixtures from said inlet conduit to said outlet conduit for deflecting the mixtures flowing from said inlet conduit through the housing to alter the direction of flow whereby the mixtures pass into and through said outlet conduit to the exterior of the housing;   a mandrel having a mesh configuration extending between the interior open end of said outlet conduit and said baffle;   filtration material coaxially disposed about said mandrel and said outlet conduit and interposed in the flow path from said inlet conduit to said outlet conduit; and   drain means located at said opposite end for removing oil and contaminants deposited in said opposite end whereby crankcase emissions from the internal combustion engine directed through the apparatus have oil, sludge and particulate matter removed therefrom prior to reintroduction into the engine through a positive crankcase ventilation system.   
     
     
       2. An apparatus according to claim 1 wherein the filtration material is disposed about the mandrel. 
     
     
       3. An apparatus according to claim 2 wherein the filtration material extends between and is in contact with the exterior surface of the mandrel and the interior surface of the housing. 
     
     
       4. An apparatus according to claim 3 wherein the filtration material extends between and is in contact with the interior open end of the outlet conduit and the baffle. 
     
     
       5. An apparatus according to claim 4 including a plurality of said intake inlet conduits for connection to a corresponding number of emission sources from an internal combustion engine. 
     
     
       6. An apparatus according to claim 5 including an auxiliary outlet from the housing adapted for connection to said engine. 
     
     
       7. An apparatus according to claim 1 wherein the ratio of the cross-sectional area of the outlet conduit to the cross-sectional area of the inlet conduit is at least two to one (2:1). 
     
     
       8. A method of removing contaminants from an emission stream from the crankcase of an internal combustion engine comprising the steps of: (1) transmitting the emission stream from an internal combustion engine to the inlet to an air-oil separator having an inlet conduit of a first cross-sectional area and an outlet conduit of a second cross-sectional area greater than said first cross-sectional area, said conduits being located at the same end of the housing;   (2) reducing the ambient pressure of the emission stream in the course of flow through the separator by flowing the emission stream from the smaller inlet conduit to the larger outlet conduit;   (3) reversing the direction of flow of said emission stream through the separator only once in the course of flow from inlet conduit to outlet conduit to exhaust the stream from the separator at the same end thereof at which the emission stream was introduced; and   (4) directing the flow of the emission stream through the separator from inlet conduit to outlet conduit so as to cause the emission stream to contact interior surfaces within the housing whereby pollutants and particulate matter in the emission stream are entrained and deposited in the separator.   
     
     
       9. The method according to claim 8 wherein the step of transmitting the emission stream includes the step of introducing the emission stream into the separator tangentially to create a vortical flow pattern through the separator. 
     
     
       10. The method according to claim 9 wherein the reversing step includes the steps of directing the vortical flow of the emission stream longitudinally through a substantial portion of the length of the separator, deflecting the flow of the emission stream to change the direction of flow and thereafter directing the flow of the emission stream through an interior conduit of the separator in the reverse of the first direction of flow.